Method of improving aluminum alloys



Patented June 7, 1927.

. UNITED STATES- PATENT orrlca,

VINGENZ FUSS, OF LAUTAWEBK, GERKANY,ASSIGNOB 1'0 VEBEIHIG'I'E ALUIIHIUH- WEBKE A. 6., OI LAUTAWEBK, GERMANY.

,METEQD OI IMPROVING ALUHINUE ALLOYS.

. no Drawing, Application fled Iay'Sl, 1924, Serial No. 717,170, and inGerman, Annie 18, 1m.

' My invention relates to the art of improving or perfecting aluminumalloys, that 15 to say, to bring the alloy into a state of reaterperfection especially as regards the p yslcal properties thereof.

"In the methods hitherto applied for the purpose, a lengthy andcomplicated operation is necessary which is objectionable anddetrimental mainly for the reason that the stretching out of the ingotsis: to be interrupted by treating the same with heat and that the finalstage of the operation is a repeated treatment with heat.

Furthermore, the hitherto known perfecting methods are applicable to thetreatment of aluminum alloys only, which contain mag- Il-SllllIl.

In consequence thereof irregularities in the operation occur whichprevent the final products to be obtained in accordance w th thehitherto practised methods from being uniform, so that the same fail toanswer the desired purpose as regards both the obtainable properties andthe final composition of the alloy.

The object ofmy invention these defects. 7

With this aim in view I stretch out the alloys or ingots, withoutinterruption by treatments with heat or by cooling, to the desired is toremedy final dimensions by way of a continuous or uninterrupted reducingprocess, then I heat the stretched alloy to a temperature of about 500C. and thereafter I cool the same as much as necessary and harden thesame at a low temperature.

In practice my method may be carried out as follows:

The ingot which preferably contains about 4% Cu and 12% Si, is heated toa temperature of about 500 C. and reduced out in a single operation tothe final sectional dimensions by pressing, rolling or the like, so thatthe reduction as regards the crosssectiona'l area of the work willpreferably amount to at least 90 p. c.

The reduced bar is then heated for about three hours to about 500 C. ora little higher just as required by the solidus-point of the alloy,whereupon it is cooled either by chilling the same in oil, water or thelike or by allowing it to cool down slowly. Y

I am aware that the operation of chilling an aluminum alloy for thepurpose of improving the properties thereof is known in the art.

The cooled alloy then is hardened without subjecting the same to anfurther stretching operation and the har ening operation may be carriedout at a temperature,

which is far below the temp ratures that are I usually employed hithertof r the purpose.

E'wwmple.An ingot of an aluminum alloy containing in hundred parts about4 parts of copper and 1 to 2 parts of silicon is heated to a temperatureof about 500 C. and rolled by a rolling mill in tr continuous operationdown to the final cross-section, which is about of the ori inalcross-sectional area. The thus rolled alloy is then subjectedto anannealing process for three hours and at a temperature of 500 C. orstill more, justzrs required by the solidus-point of the alloy undertreatment whereupon it is cooled by chilling the same in oil or water orby allowing it to cool down slowl The metal-sheets obtained this way aresu jected for 48 hours to a temperature of 90 to 100 0.

As already intimated m method is particularly adapted and suita le foruse in erfecting or improving aluminum alloys, w ich do not contalnmagnesium and it is possible. to produce thereby, notwithstanding thesimplified mode of operation, an equivalent or substitute for the knownmagnesium aluminum alloys like duraluminum which have the'greatdisadvantage, that the composition desirable in the final productscarcely or only with diflicultynca'n be obtained, since an incalculableportion or percentage of'the magnesium employed is consumed for'thedeoxydation of the alloy and a further percent-age thereof is lost byburning during the mixing and stirring operation.

From the foregoing it is believed that the advantages and novel featuresof my invention will be readily understood and therefore further detaildescription is deemed unnecessarv.

It will be evident that my invention,

whilst still being adhered to in its main essentials may be varied andadapted in many ways, according to the particular requirements desiredor most suitable under different circumstances.

What I claim is The process of treating aluminum alloys consisting inproducing an ingot of aluminum alloys with substantially four percent ofcopper and two percent of silicon, subfor the period of about threehours, cooling the same, and then maintaining the same at 15 atemperature of about 90 to 100 degrees C. for the period of about 48hours.

In Witness whereof I affix my signature.

DB. Inc. VINGENZ FUSS.

